Lifeboat launching device



Sept. 3, 1940. T. NiBLETT 3 5 LIFEBOAT LAUNCHING DEVICE Filed Aug. 28, 1959 s Shets-Sheet 1 Inventor A iiorney;

Sept. 3, 1940. T. NIBLETT LIFEBOAT LAUNCHING DEVICE Fil'ed Aug. 28, 1959 3 Sheets-Sheet 2 v A iiomeys Sept. 3, 1940 T. NIBLETT 2,213,636

LIFEBOAT LAUNGHING DEVICE Filed Aug. 28, 19s9 s Sheets-Sheet s I u I 7 Inventor 7/ 1 7 54mm w By M1,,

A tiorneys Patented Sept. 3, 1940 KJNETEE STATES 2,2l3,63th

PATENT orrics 9 Claims.

This invention relates to a launching device for launching boats from ships, the general object of the invention being to provide means whereby the boat can be easily and quickly swung over the side of a ship and then lowered and released from the supporting means and in the minimum amount of time and with the least manual effort and without the use of blocks and falls, etc.

Another object of the invention is to provide a flexible screw shaft with a rotary nut member for moving the shaft longitudinally, for performing certain movements of the launching action, with hollow members for enclosing parts of the screw shaft to protect the same from the elements.

Another object of the invention is to provide a hollow davit for supporting the nut member and the motor rotating the same and for receiving portions of the screw shaft, with means for moving the davit inwardly and outwardly, said means including flexible screw shafts and rotary nut members.

Another object of the invention is to provide means whereby the flexible screw shaft used for lowering and raising a boat can be easily and quickly attached to or detached from parts of the boat, said means being of such a nature that they will not interfere with the occupants of the boat and will take up but little room in the boat when the boat is detached from the screw shaft. 30 This invention also consists in certain other features of construction and in the combination and arrangement of the several parts to be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claims.

In describing the invention in detail, reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which:

Figure is a diagrammatic view partly in elevation and partly in section showing the invention in use for launching a boat from a ship.

Figure 2 is a plan view of a lifeboat constructed in accordance with the invention.

Figure 3 is a longitudinal sectional view through the boat shown in Figure 2.

Figure 4 is a vertical sectional view through the nut member, the motor for driving the same and the casing carried by a davit and this view also showing portions of the flexible screw shaft with parts thereof broken away and with end portions in section.

Figure 5 is a fragmentary top plan view of a seat or thwart of the life boat with the means for coupling a flexible screw shaft thereto, the cover of such means being in open position.

Figure 6 is a transverse sectional View through the lifeboat and the coupling means with the cover in closed position and the coupling means 5 in inoperative position.

- Figure 7 is a view similar to Figure 6 but showing the coupling means engaged by'the lower end of a flexible screw shaft so that the life boat is connected with the screw shaft. 10

Figure 8 is an elevation of the lower part of a screw shaft. v

Figure 9 is a bottom plan view of the lower end of the female coupling member at the lower end of the screw shaft. 15

Figure 10 is a View in elevation with parts broken away of the sliding sleeve forming part of the coupling means of the lifeboat.

Figure 11 is a top plan view with parts insection of the means for moving the davit on the 20 curved supporting members.

Figure 12 is a section on the line [2-42 of Figure 11.

Figure 13' is a view on the line Iii-I3 of Figure 11.

Figure 14 is a transverse view through Figure 11. In these views the letter A indicates a part of a ship and-the letter B the lifeboat of the ship 7 and in carrying out the invention several davits I are provided for each lifeboat, each davit being of hollow construction as shown and having a bell mouth 2 at its upper end with its lower end pivoted to a bracket 3 attached to a part of the deck. .Said bracket including a tubular part passing through the deck and to which a tube 4 may be connected for guiding the slack of the flexible screw shaft 5 when said shaft has a portion depending from the lower or inner end of the davit. Said shaft 5 is formed of a wire core 5' made up of a plurality of strands of wire to form'a wire rope or cable, and a bar 5" of steel wound around the core and suitably connected therewith, this bar or rod 5" being preferably a wire drawn rod of a shape to form a thread of the desired configuration, the drawings showing this thread as a buttress thread. Also, as shown in Figure 4, the rod is Wound around the core in an opposite direction from that in which the strands are wound in producing the core.

A casing fi is provided with the trunnions which engage bearings in the bell mouth of the davit so that the casing is suspended from the davit and has its upper cover part 8' located in said bell mouth. Said cover part 6 is formed with an opening 8 for the passage of'the flexible shaft 5 and the lower end of the casing turns upwardly and inwardly to form an opening 9 for the passage of the shaft. A nut member ID is rotatably arranged in the casing and anti-friction bearing means H are located between the lower end of the nut member in and the upwardly curved part of the bottom of the casing, as shown in Figure 4. A plate-like member I2 is seated on a ledge E3 in the top of the casing and the nut member passes through a centrally arranged hole in the member l2 and has its upper end provided with an enlargement l4 and antifriction means are located between this enlarged part I4 of the nut member. and the member l2. Thus the nut member is rotatably arranged in the easing and is supported by antifriction bearing means. An electric motor is located in the casing for rotating the nut member and said motor is indicated generally at M and includes the armature l6 suitably connected with the nut member, the fields l1 and the brush means 18, the wires leading .to the motor from a suitable source of supply being indicated at IS in Figure l.

The nut member may be formed in sections and preferably the lower section is formed with a spiral passage therein for engaging a part of the spirally threaded shaft 5, as shown in Figure 4 with the'rest of the nut member having an enlargedspiral passage therein, this passage being so much larger than the thread of the shaft 5 that said thread could pass through the passage of the nut member if it were not for the lower reduced part of the passage. Roller bearings are placed between the walls of the spiral passage of the nut member and the threads of the shaft 5 and ball bearings 23 are associated with the roller bearings, the ball bearings engaging the ends of the roller bearings and both sets of bearings being held in place by a suitably formed retainer 22. A filler member 23 is placed in the top of the passage of the nut member and a retainer plate 24 is fastened by bolts to the top of the nut member for holding the filler member 23 in place and also holding lubricant in place which has been pressed between the bearings and the walls of the passage and the threads of the shaft 5.

Thus it will be seen that the anti-friction bearing provided by the rollers and balls will reduce friction to the minimum and the rotary movement of the nut member will move the shaft 5 longitudinally through means of such antifriction means and thus the shaft 5 can be raised or lowered in accordance with the direction of rotation of the motor. It will be understood that as the shaft 5 is being raised by the nut member that part of the shaft passing from the top of the casing will move along the curved part of the davit and then downwardly through the davit and if the slack part of the shaft is of greater length than the length of the davit then the shaft will finally pass through the bracket 3 and into the tube 4.

Thus only the part of the shaft which depends from the nut member or casing 6 is exposed to the elements as the rest of the shaft is enclosed in the davit and the member 4 and there are no parts of the shaft to be in the way of passengers or crew.

The outer circumference of the enlarged part M of the nut member forms1a brake drum for a shaft 29 which has an arm 30 attached thereto to which a flexible member 3| is connected, this flexible member passing through an opening in the cover part 6 and through a table 32 to an operating lever 33 so that by properly rotating the shaft 29 the band can be expanded or contracted and when contracted will hold the nut member against rotary movement, after the motor has been stopped, thus holding the screw shaft 5 against downward movement under the weight of a boat attached to its lower end.

Each end of the shaft 5 has-a part of the thread forming member 5" cut therefrom and then the strands of the core 5' are passed through perforations in a disk 35, the perforations preferably being inclined to the axis of the disk and the ends of the wires passing through the perforations are knotted to prevent the ends from being pulled through the perforations. A pair of gripping jaws 3B is associated with each disk 35 and these jaws are formed with internal parts which conform to the spiral thread of the shaft 5 so as to engage portions of this thread and then a coupling member 31 is placed over the lower or outboard end of the shaft-and a sleeve 38 over the other or inboard end of the shaft, the parts 35' and 36 in the sleeve 38 being similar to the parts 35 and 36 in the sleeve 31. The disk and gripping members with the internal parts of the sleeve at each end of the shaft are preferably formed with interrupted threads for interlocking with each other in the manner set forth in my Patent Number 2,115,743, dated May 3, 1938. The inboard end fixture has a pipe section 39 in the sleeve 38 which abuts the disk 35 and a bolt 40 passes through the sleeve and this pipe section, as shown in Figure 4. If desired rollers can be placed on the ends of this bolt 40 to engage portions of the davit which should be formed as track parts for receiving such rollers.

The exterior shape of the sleeve 31, which forms a c'oupling for connecting the shaft to the boat B is preferably of the shape shown in Figures 8 and 9 which shows the sleeve having a fiat part 31' and a wedge part 31" at opposite side portions and the lower end of this sleeve 31 has its bore formed with interrupted or mutilated threads 4| as shown in Figures 4' and 9.

The boat B is provided with means for receiving the coupling members 37 at the lower ends of the threaded shafts and as the drawings show the boat adapted to be launched by two davits the boat is provided with a pair of the coupling members. As shown each set of members includes a standard 42 connected with the bottom of the boat and extending upwardly into a hole in a seat or thwart 43 of the boat. A tubular member 44 is rotatably arranged in said opening I is slidably arranged on the shaft 42 but is held against rotary movement thereon by means of a key 49 on the shaft engaging a keyway in the bottom of the sleeve. A disk 50 is fastened to an intermediate part of the shaft 42 and is located in the sleeve and forms a seat for the lower end of a coiled spring 5! encircling the shaft and located in the sleeve with the upper end of the spring bearing against the flange 48. The upper part of the shaft 42 is enlarged and forms a male member which is provided with the mutilated threads 53 and the spaced enlargements 54 on its bottom. These enlargements being engaged by the flange 48 of the sleeve when the sleeve is in lowered position as shown in Figure 7. A hinged cover 55 is provided for closing the upper end of the tubular part 54 of the wrench when desired so as to prevent foreign matter from getting into the interior of the sleeve and on the parts there- The exterior of the sleeve is formed with a bayonet groove 53, see Figure 10, the upper horizontal part of which terminates in a hole 51. A spring actuated latchbar 58 is carried by one of the arms of the Wrench, the spring acting to hold the inner end of the latch bar in the groove 56 and to project it into the hole 5! when the hole comes opposite the latch, this hole 57 being formed in the flange carrying part of the sleeve. A flexible member 59 is connected with the latch bar and passes over suitable guiding pulleys 60 inthe boat to a block and tackle Bl located at the rear of the boat so that the coxswain can manipulate the block and tackle, or a lever, connected with the cables or flexible members 59 to actuate both of the wrenches and the latch bars 58.

The interior formation of the parts 44 of each wrench is made similar to the exterior shape of the member 3? at the lower end of the flexible shaft 5 so that this part 37 can be placed in the tubular part of the wrench and then when the wrench is turned by a pull upon the flexible member 59 the part 31 will be rotated with the tubular part of the wrench. As the part 3'! is pushed into the tubular part of the wrench it will force the sleeve ll downwardly which will compress the spring 5? and the spaces between the mutilated threads 49 in the member 3'! will pass through the grooves formed by the mutilated threads 53 of the shaft s2 and then when the member 3'? is turned by turning movement of the wrench the threads ll of member 31 will interlock with the threads 53 of the standard or shaft #32 and thus the shaft 5 will be firmly locked to the coupling means of the boat. As the sleeve moves downwardly the latch pin will at its inner end pass up the groove 56 and then when the wrench is turned to lock the female member 3'! with the male member or standard 42 the pin will move through the horizontal part of the groove 56 until it reaches the end of the groove and then its spring will project it into the hole 5i in the sleeve and this looks the parts with the mutilated threads of the member 37 inter-engaging with the mutilated threads 53 of the member 42.

It will be understood that the engagement of the members 3'! of the shafts 5 with the coupling members of the boat B is done by hand and the wrenches are turned by hand with the operator sitting close to the parts. However, when the boat is to be released from the shafts 5 then the coxswain can exert a pull upon the flexible members 5% which releases the latch bars 58 and at the same time rotates the wrenches so that the mutilated threads of the members 3'! and 42 are disengaged and the sleeves 47 released from the latch pins so that the springs 5! in the sleeves will force the sleeves upwardly and cause said sleeves to push the members 3'! from out of the wrenches and. thus the boat will be free of the shafts 5. Of course, if the boat is released from the members 3'1 while it is suspended in midair then gravity or the dropping of the boat will free the members 31 from the wrenches after the wrenches have been moved to releasing position.

Each davit can be swung inwardly and outwardly as shown in full and dotted lines in Figure 1 and. during this movement wheels It carried by the davits engage the arcuate track forming members H supported from the ships deck, one on each side of a davit and these track members are of hollow construction as shown. Each carriage includes a two part tubular clamp 12 for clamping around an intermediate part of the davit. and the shafts 13 for the wheels E9 extend from opposite sides of the clamp. Shanks it also extend from opposite sides of the clamp and below the shafts l3 and these shanks carry the gripping means shown generally at 75 which are located in the track members, the shanks passing through slots 26 in the inner sides of the track members and these slots communicate with the bores ll of the track members. These clamping means 75 engage the ends of flexible threaded shafts '58 which pass through the bores ll of the track members H and these clamping members 55 are made somewhat similar tothose which hold the members 37 and 38 to the ends of the shaft 5. As shown each clamping part 15 includes a disk l9 having holes therein for receiving the wires of the core 18' of the shaft IS with the sectional members somewhat similar to the members 36 engaging the disk 79 and pins 8i passing through these members 80 and through the thread forming bar 58" of the shaft 18 and the threads of said members 89. Thus the flexible threaded shafts T8 are connected with the clamp member '42 so that the member 72 with the davit is moved along the track members as the threaded shafts '78 are moved in one direction or the other by the rotary nut members 82 rotatably supported in a housing 83 supported by a supporting structure 84 from the deck of the ship as shown in Figure l. A motor M has a pinion 85 on its shaft which meshes with the gears 86 connected with the nut members so that the two nut members are rotated from the motor to impart simultaneous movement to the two screw shafts 78 which, in turn, impart movement to the clamps T2'and the wheels it! which move the davit inwardly or outwardly. Each nut member 82 is formed with the internal spiral threads in which are located the rollers 8'5 which also enter the threads of the shaft 78 which are formed by the bars 18" suitably attached to the wire core 78. It will be seen that this flexible threaded shaft 18 is similar to that shown at 5 excepting that the threads are of square formation instead of the tapered formation shown in Figure l. The rollers 8? are carried by a retainer 88 and anti-friction bearings 89 are located between the ends 01 the nut member 82 and the adjacent parts of the housing. Plates 9!] are fastened to the ends of the nut member and have their inner circumferences shaped to engage the threads of the shaft l8 as shown in Figure 13.

Suitable switch means as are provided for controlling the current to the reversible motors M and the inner ends of the track members H are.

extended downwardly through the deck as shown at H in Figure 1 so that the flexible shafts l8 will pass downwardly through these parts H as the davit is being moved inwardly to the dotted line position shown in Figure 1.

If it is not desired to use the motor construction shown in Figure 4 then the nut member shown in this figure can be driven by gearing from a motor, somewhat similar to the arrangement shown in Figure 11.

The control for the motors M for moving the two davits and the motors M for actuating the nut members which control the movement of the shafts 5 should be such that they can be actuated by a single operator so that the boat when being launched will be moved on an even keel and the coxswain by manipulating the cables 59 can release both ends of the boat from the shafts 5 simultaneously. Of course, in launching the boat after the boat has been connected with the ends of the shafts 5 the davits are swung outwardly of the dotted line position to the full line position shown in Figure 1 and then the motors M are actuated to lower the shafts 5 and then the coxswain manipulates the flexible members 59 to release the boat from the lower ends of the shafts 5. Of course, in raising a boat the operation is reversed, the boat being connected to the lower ends of the shafts 5 and then the motors M are started so as tocause the shafts 5 to raise the boat and then the davits are swung inwardly and the boat placed on a suitable chock or cradle. By using the flexible shafts and having them enter hollow davits and hollow track members there are no loose ends or cables or the like for getting in the way of persons on the ship or boat or injuring persons and the parts are enclosed to protect them from the elements.

The female member 3? and the male member or upper part of the shaft 42 can have their thread arrangement formed similar to the before-mentioned patent.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction and in the combination and arrangement of the several parts provided that such changes fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

1. A boat launching device comprising a davit pivotally supported at its lower end, means for swinging the davit inwardly and outwardly, a flexible screw shaft passing through the davit and extending from the outer end thereof, a nut member, a housing for the same pivotally supported from the outer end of the davit, means for rotatably supporting the nut member in the housing, the screw shaft passing through the nut member and means for rotating the nut member to impart longitudinal movement to the screw shaft.

2. In a boat launching device, a hollow davit having a mouth, a housing depending from the mouth and pivotally supported therein, a nut member rotatably arranged in the housing, a flexible screw shaft having a part passing through the davit and a part passing through the nut member, means for rotating the nut to impart longitudinal movement to the flexible screw shaft and anti-friction means between the nut member and the screw shaft.

3. In a boat launching device, a hollow davit having a bell mouth, a housing depending from the bell mouth and pivotally supported therein, a nut member rotatably arranged in the housing, a flexible screw shaft having a part passing through the davit and a part passing through the nut member, means for rotating the nut to impart longitudinal movement to the flexible screw shaft and anti-friction means between the nut member and the screw shaft, said anti-friction means including roller and ball bearings.

4. In a boat launching device, a hollow davit having a bell mouth, a housing depending from the bell mouth and pivotally sup-ported therein, a nut member rotatably arranged in the housing, a flexible screw shaft having a part passing through the davit and a part passing through the nut member, means for rotating the nut to impart longitudinal movement to the flexible screw shaft and anti-friction means between the nut member and the screw shaft, said anti-friction means including roller and ball bearings, said screw shaft including a core formed of strands of wire wound together and a thread forming bar wound around the core to form the thread.

5. In a boat launching device, a davit of hollow construction, a housing depending from the mouth of the davit and pivotally supported therein for rocking movement, a nut member rotatably arranged in the housing, means for rotating the nut member, a flexible screw shaft passing through the davit and through the nut member and moved longitudinally by rotary movement of the nut member and means for detachably connecting the lower end.- of the screw shaft to a boat.

6. In a boat launching device, a davit of hollow construction, a housing depending from the mouth of the davit and pivotally supported therein for rocking movement, a nut member rotatably arranged in the housing, means for rotating the nut member, a flexible screw shaft passing through the davit and through the nut member and moved longitudinally by rotary move-ment of the nut member and means for detachably connecting the lower end of the screw shaft to a boat, said means including a male member in the boat having mutilated threads, a female member on the lower end of the screw shaft having interrupted or mutilated threads, Wrench means in the boat for receiving the female member and rotating the same to interlock the mutilated threads of the female member with the male member.

'7. In a boat launching device, a davit of hollow construction, a housing depending from the mouth of the davit and pivotally supported therein for rocking movement, a nut member rotatably arranged in the housing, means for rotating the nut member, a flexible screw shaft passing through the davit and through the nut member and moved longitudinally by rotary movement of the nut member and means for detachably connecting the lower end of the screw shaft to a boat, said means including a male member in the boat having mutilated threads, a female member on the lower end of the screw shaft havinginterrupted or mutilated threads, wrench means in the boat for receiving the female member and rotating the same to interlock the mutilated threads of the female member with the male member, a spring-pressed sleeve surrounding the male member and means for locking the sleeve in position, when the female member is in engagement with the male member for preventing movement of the wrench.

8. In boat launching means, a davit pivotally supported at its lower end, said davit being of hollow construction, a housing supported for rocking movement in the mouth of the davit, a nut member in the housing, means for rotating the nut member, a flexible screw shaft passing through the davit and through the nut member, means for connecting the lower end of the shaft to a boat, a curved track for the davit of hollow construction, a carriage attached to the davit and engaging the track, flexible screw shafts passing through hollow portions of the track and connected with the carriage, stationary supporting means, nut members supported thereby and encircling the last-mentioned flexible screw shafts, a motor for driving the last-mentioned nut means.

9. In boat launching means, a davit pivotally supported at its lower end, said davit being of hollow construction, a housing supported for rocking movement in the mouth of the davit, a nut member in the housing, means for rotating the nut member, a flexible screw shaft passing through the davit and through the nut member,

means for connecting the lower end of the shaft to a boat, a curved track for the davit of hollow construction, a carriage attached to the davit and engaging the track, flexible screw shafts passing through hollow portions of the track and connected With the carriage, stationary support ing means, nut members supported thereby and encircling -the last-mentioned flexible screw shafts, a motor for driving the last-mentioned nut means, each last-mentioned nut means including a member having a spiral thread therein, rollers located in saidthreadand engaging the thread of the flexible shafts.

THOMAS NIBLETT. 

